inferior frontal gyrus


in·fe·ri·or fron·tal gy·rus

[TA] a broad convolution on the convexity of the frontal lobe of the cerebrum between the inferior frontal sulcus and the sylvian fissure; divided by branches of the sylvian fissure into three parts: opercular part [TA] (pars opercularis [TA]), triangular part [TA] (pars triangularis [TA]), and orbital part [TA] (pars orbitalis [TA]); the first two constitute a portion of the frontal operculum. Synonym(s): gyrus frontalis inferior [TA], Broca convolution, inferior frontal convolution

inferior frontal gyrus

The inferior-most of the three major longitudinal gyri of the lateral surface of the frontal lobe of each cerebral hemisphere; it is part of the prefrontal cortex. In the dominant hemisphere, the posterior two-thirds of the inferior frontal gyrus are Broca speech area, which is involved in activating the muscle groups used when speaking See also: gyrus